Tech Tip: Make Sure You Have the Tools and Equipment Needed to Service Today’s Electrical Systems

By Mike DuBois

One day we are fat, dumb and happy using a piece of wire with a 12-volt bulb on the end of it to test things with. Now we are faced with deciding between using the 10 meg-ohm computer safe test light, the power injector or a logic probe complete with polarity protection, audible alarm, light and 20-foot memory cord. Geeesh! How did things get so confusing so fast? Progress my boy! That is the root of our problem here! As the cars and systems have gotten more and more complicated, so have the tools and equipment needed to work on those cars ….

Today’s professional technician is expected to be able to understand electrical theory, electronics, physics, as well as understand and interpret readings from complex electrical test equipment. Add to that volts and amps and ohms…OH MY!The good news is that there are some general classifications of electrical test equipment that can at least narrow down the choices to a more manageable number of tools to consider. There are generic system testers, there are specialty testers and there are diagnostic testers. These main three groups are a good starting place to think about the tools and equipment needed to test today’s modern automotive electrical systems.

Generic or general testers normally are designed to perform a range of tests or work on a variety of vehicles and systems. These testers might include such things as multimeters, battery load testers and voltage test lights. Again, the main thing about these tools is that they can work on different vehicles, and perform general tests on different systems.

This is the largest category of electrical testing tools and equipment. These tools provide the foundation for all the more complex testing that may be necessary later on. A technician will do well to start building his or her collection of tools here. The basics are still necessary even on the most complicated vehicles. The basics should include a 12-volt test light, a multimeter that is capable of performing a host of tests including the basics such as volts, amps AC and DC current measurement, diode testing, rpm, temperature and starter draw testing.

The meter should have overload protection via fuses, it should also be able to store min/max values on data, and meters that show a graphical representation are needed to perform many tests today. From here, a tech should consider a collection of ancillary items to support and complement the multimeter. These items might include an rpm inductive pickup, a K-style temperature probe and an amp clamp adapter (this allows for starter draw testing). Once these items are in place, make sure that the kit includes an assortment of test leads and extensions, back probes, clamps, etc. These items ensure that the technician can always hook his or her test equipment to whatever item is being tested.Another incredibly powerful tool is a power injector. These tools allow the technician to provide power to a component for testing. Most of these units have a ground wire available directly next to the power source. These tools are some of the best productivity tools in the current technician’s toolbox. These tools have features such as lights, audible alarms and polarity indication.

Specialty Test Equipment
Specialty testers such as oxygen sensor testers, ABS wheel speed sensor testers and fuel injection signal testers are designed to do one specific test. These tools are indispensable for verifying a diagnosis prior to replacing an expensive component. Many of these testers aren’t used every day, but on those occasions where you really need it, you will be glad you have it.

Diagnostic Test Equipment
This is some of the most expensive, complicated and powerful equipment and tools that a technician can purchase. The true value of this equipment is in the description. Diagnostic test equipment will actually provide the user with possible answers or diagnosis of what might be wrong with a vehicle. These tools are different from other test equipment in that they usually have the ability to receive, interpret and analyze multiple sources of data input.

One example of diagnostic test equipment is the latest generation of battery testing equipment. These tools are incredibly complex, they are using microprocessors and, in some cases, are performing multiple tests at one time to verify the condition of a battery. The early battery testers placed a load on a battery and then the user was left with making a decision based on the analog results of that test. Compare that with today’s testers, which are evaluating the battery on several levels including state of charge, voltage, amperage, percentage of life left, maximum potential power output and many other tests. This is just one example of a diagnostic tester used for electrical systems on today’s modern vehicles.Regardless of a technician’s knowledge level, picking test tools is not an easy task. Many times the testers that are available today are so complicated that even the professional sales and tool people can’t always know all the features and benefits of a specific tool or piece or equipment. The best course of action in those cases is for the technician to contact the supplier directly to learn more about the tool before making a buying decision. Another great way to learn about test tools is by attending seminars and continuing education programs. These are opportunities for the tech to see, touch and use the tool in a relaxed environment.

Award-Winning Shop Lives by Golden Rule

Posted 6/1/2008By Leona Dalavai Scott

Midtown Auto Service Named ‘Best Auto Shop.’

Shop Stats

Name: Midtown Auto ServiceLocation: Houston, TexasWeb site:www.midtownautoservice.netSquare footage of shop: 6,000 square feetRepairs per week: 150 carsNo. of years in business: 21 yearsOn his success rate with retaining technicians: “I offer my technicians two weeks of paid vacation during Christmas and New Year’s after they’ve been employed with me for a year. Also, I treat them and their spouses to dinners and lunches on random occasions. I try to let them take care of family or personal business without penalties. All of my techs have their own computers with Internet access to Alldata and Identifix. Things like that really make a person want to stay.”

Mikey credits his prime location for business staying strong even during tough economic times.

Mikey Yu is not your average shop owner. With a criminal justice degree from the University of Houston, he always wanted to be a cop.

But when his dad retired in 1998, Mikey thought that it would be a smart move to buy the shop from him. Within four years of taking over the shop, he expanded the facility from 2,900 square feet to 6,000 square feet. Along the way, he earned his ASE
certification to become an auto technician.

Mikey is also a state-certified inspector and his shop, Midtown Auto Service, is a state-certified emissions and repair facility. The shop is known in the community for its engine and emissions diagnostic capabilities and for solving electrical driveability issues for all makes and models.

Mikey says his shop’s strength stems from the way it treats its customers and its technicians. He conducts his business by the golden rule: “Do to others as you would have them do to you.” He believes you should treat your customers and employees the way you would want to be treated.

“And if you treat your employees as family members instead of just a number, I think that productivity increases,” Mikey says. Midtown Auto Service employs two L1 master auto techs and another master auto tech. Mikey’s wife, Sharon, handles all of the administrative work in the office while Mikey takes care of the “heart of the business,” which he sees as fielding questions and calls from customers and handling technician concerns and problems.

“Our line of work is difficult,” Mikey explains. “The customers who bring their cars and trucks to us normally know nothing about repairing their cars but have heard horror stories about other automotive service shops in the past. So, you start building a rapport with customers and listen to issues about their car. Just listen. Listening is very important. That can help break the barrier of customer distrust from the beginning.”

Master ASE Certified Tech Byung Young working on a car using his 1/2 cordless SnapOn gun.

As a result of his business philosophy, Mikey has experienced great success with Midtown Auto Service. In 2007, the shop was named the “Best Auto Shop” by Citysearch, a popular Web site that enables users to post opinions on just about anything, including recommendations for services such as auto care. In 2006, the shop was named “Best Auto Repair Shop” by the local newspaper. In addition, the shop is a AAA-approved auto repair facility and a recognized emissions repair facility.

Mikey also shares his knowledge and expertise of cars through articles in Undercar Digest and Automotive Report. He has also been featured on “Car Talk,” an entertaining radio show about automotive service issues that is broadcast on National Public Radio.

ASE L1 MASTER AUTO TECHNICIAN; Panda Lee is working on an electrical drain/short on a 2006 Jaguar S-type.

As he looks toward the future, Mikey would like to expand his shop. He is currently trying to acquire the land next to his so he can double his shop size to 12,000 square feet or more. However, real estate in his area has skyrocketed so he is proceeding on those plans with caution. Despite the downturn in the economy, Mikey says Midtown Auto Service’s business has been good as a result of its prime location between downtown and the medical districts of Houston.

As Mikey celebrates the success of Midtown Auto Service, the thing he is most proud of, he said, is the teamwork his employees exhibit in working with the motoring public. As his accolades and accomplishments show, this teamwork is paying off nicel

We are a Texas Approved AAA Auto Repair Facility in Houston. Also, we are an Independent Auto Care/Repair Factory Dealer Service Center for AC Delco inHouston, with ASE Certified Technicians. Recognized by the state of Texas, Midtown Auto Service & Repair is licenced to issue auto inspections on all types of vehicles.

We have been featured in magazines such as Undercar Digest, Tech Shop and Automotive Report. These magazines were contacted by other auto repair shop owners and customers who reported us worthy as a featured story. Midtown Auto Service is honored by these recognitions of these auto technical trade magazines. Which is considered a great achievement from our peers.

Also, Citysearch has awarded Midtown Auto Service as Best Auto Repair Shop 2006-2007. Citysearch awarded us with a plaque, “Best Auto Repair 2006 –Audience Winner.” In 2007, Citysearch again awarded us with two rewards, “Best Auto Repair 2007 – Audience Winner & Editorial Winner.” Thus, making Midtown Auto Service the only auto service care facility in Houston, Texas to win two years in a row by Citysearch.

In addition, Midtown Auto Service have won other coveted national recognitions, such as, “Yahoo 2005 Best & Trusted Auto Care Facility” and by “TheLocal Newspaper – The Best Auto Service 2006.” We are also listed in a national radio broadcast, “Car Talk” as listed as a good repair shop to visit in Houston in their “mechanics file.”

Come and try us out and see the difference, we are conveniently located between the downtown & medical center, also known as Midtown.

In conclusion, we service all foreign, domestic and most european cars. In addition, we take checks and all 4 major credit cards,( checks, MasterCard, Visa, Discover, & American Express)

Welcome! It’s our goal at Midtown Auto Service & Repair Shop in Houston to always provide great service and high-quality workmanship at a fair price. Midtown Auto Service & Repair is a family-owned business that has specialized in providing personalized service to our customers.

Since 1987, Midtown Auto Service & Repair Shop in Houston has been committed to providing the highest quality automobile repair service at affordable prices. We have established our auto repair business on sound ethical and moral principles. Simply put, our Houston auto repair business focuses on customer service, and your satisfaction is paramount. We want you to be pleased with our services so that you will continue to use us for your automobile repair-service needs in the future and tell your friends.

Our skill and knowledge about automobiles enable us to address a broad range of auto repair-services of mechanical issues, which means you’ll experience a higher, more comprehensive level of service and greater value with us.

How do we do it? We listen. Hearing your opinions, observations and concerns make it possible for us to work with you as a team. By earning your trust, we can better guide you toward solutions that meet your specific needs about your car auto repair services.

At Midtown Auto Service & Repair , you’ll always get a clear explanation of what’s happenings with your car, as well as whatever options you should be aware of when making your maintenance and auto repair decisions. That’s our commitment to you. Please browse around our website to learn more about us and our commitment to provide you with the best service possible.

One of the highest recognitions for an auto repair shop in Houston is given by the State of Texas to be a Recognized Auto Repair and Emmissions Repair Facility. In turn, it gives us privileges from the State of Texas for issuing Automotive Repair and Replacement Assistance in Houston & the surrounding areas. In 2007, there were less than 100 automotive repair shops in Houston that had this license by the State. That is a big disproportion considering there are over 3400 auto repair shops in Houston and the surrounding areas. Another factor to being a highly recognized Houston auto repair shop is being chosen by General Motors Inc. as an independent Auto Repair Service Center: AC Delco Factory Houston Auto Repair Facility. NAPA Auto Parts also endorses our company as an Approved Napa Auto Car Care Repair Centerin Houston which means that their company certifies us to do their repair warranties or any needed repairs. Also, our shop is an AAA Approved Auto Repair Facility that employs only ASE certified auto technicians. Operating since 1987, we are conveniently located between the downtown & medical center, also known as Midtown.

Diagnostic Solutions

STEERING GEARSKeeping Your Customers’ Vehicles on The Straight & Narrowby Gary Goms, Import Specialist ContributorModern automotive steering gears evolved from the quaint tiller-controlled steering systems used in the first automobiles to the hydraulically controlled systems now used in most import vehicles. Unfortunately, steering tillers that attached to axles with little or no steering geometry didn’t provide much steering feedback from the road surface. When vehicle speeds approached 20 mph, auto manufacturers began to incorporate more sophisticated steering systems to help the driver keep the vehicle traveling in a straight line.As vehicles became heavier and more difficult to steer, auto manufacturers developed different types of steering gears designed to change the rotating motion of the steering wheel and shaft into a lateral motion transmitted through the steering linkage to the steering knuckles and front wheels. This system has prevailed to this day.KINGPIN INCLINATION
As steering gear technology progressed, innovations in steering geometry also aided steering gear functions. The popular introduction of kingpin inclination (KPI) during the early 1920s, for example, eased steering effort by tilting the kingpin inward at the top, so that a line drawn through the kingpin angle intersects with the center of the tire tread. KPI is also present in ball joint or MacPherson strut systems, with the angle of the upper and lower ball joints or MacPherson strut intersecting with the center of the tire tread.

KPI actually accomplishes three separate, but related, steering functions. First, KPI reduces steering effort by allowing the tire to pivot on the center of its tread rather than be swung around the axis of a vertical kingpin. Second, KPI greatly reduces the probability that a wheel striking a pothole may suddenly spin the steering wheel out of the driver’s hands. Third, KPI actually lifts one side of the vehicle and lowers the other as the wheels are turned. This lifting effect, combined with caster angle, forces the front wheels to return to a straight-ahead position. For all of the above reasons, steering effort increases and the steering wheel becomes more sensitive to road shock whenever offset custom wheels are installed on a vehicle.

THE ROLE OF CASTER ANGLE
Caster angle also plays a function in all steering gear systems. Positive caster angle can be easily visualized in the backward tilt of a bicycle’s front fork. Positive caster angle, of course, allows the bicycle to steer itself when the rider takes his hands off the handlebars. Although some auto manufacturers may employ negative caster angle to accomplish the same purpose, caster helps force the front wheels to return to center when the driver releases the steering wheel.

CONVENTIONAL STEERING GEARS
Although conventional parallelogram steering linkage systems are being replaced by the more modern rack and pinion steering gears, many heavier vehicles such as luxury sedans and pickup trucks still use conventional steering gears. Early steering gears were crude, bronze-bushed units that required a great amount of steering effort to turn the wheels. As vehicles became heavier, ball and needle-roller bearings were used to reduce friction in the steering gear assembly. In addition, a recirculating ball-bearing worm gear assembly was introduced that greatly reduced friction between the worm gear mounted on the steering gear input shaft and the sector gear mounted on the steering output shaft.

As vehicle speeds increased, it became very important for the steering gear to transmit a sense of “road feel” to the driver. Without a fine-tuned sense of steering wheel center, it became difficult for a driver to drive in a straight line at high speed. To accomplish this, engineers designed a worm and sector gear that would develop zero clearance or lash when the steering gear operated in the centered or straight-ahead position. The fact that the steering gear ‘tightens” up when the front wheels are in the straight-ahead position gives the driver a much finer sense of when the vehicle is tracking in a straight line.

As the wheels are turned, the steering gear rolls off the “high spot” and develops clearance between the worm and sector gears. This added clearance reduces friction and helps the front wheels return to the straight-ahead position when the driver releases the steering wheel. In addition, the high spot in the steering gear tends to stop or hold the steering gear in the straight-ahead position by increasing friction between the worm and sector gears. This particular feature helps prevent the driver from over-steering the vehicle.

RACK-AND-PINION STEERING GEARS
Rack and pinion steering gears were popularly introduced into the import market during the 1950s because they provided fast steering wheel response and had fewer parts. In this system, a rack gear is attached to the right and left steering knuckles by tie rods that swivel to allow vertical movement in the suspension system. The pinion gear, of course, is attached to the steering shaft and moves the rack in a lateral direction in response to steering wheel input. Like the conventional steering gear, the rack and pinion is machined to decrease gear lash as the steering wheel returns to the center position.

STEERING ASSIST
Steering assist systems incorporate a hydraulic pump driven by an engine accessory drive belt to provide pressure to a steering assist cylinder attached to the sector gear in conventional systems or the rack gear in rack and pinion systems.

To provide full steering assist, the power steering pump must produce at least 1,000 psi pressure upon demand. Because a power steering pump is used only a small percentage of time, the pump is equipped with a hydraulic boost or computer-controlled, pulse-modulated valve assembly that allows it to free-wheel during highway driving. To fine-tune steering wheel response, the steering gear shaft is equipped with a torsion bar that opens a metering valve as torque is applied to the steering wheel. Due to the action of the torsion bar, the amount of oil pressure metered to the steering assist cylinder is directly proportional to the torque being applied to the steering wheel.

The metering valve assembly is very sensitive because it’s often equipped with compressible reaction discs that further increase the steering gear’s sensitivity to steering wheel torque. Some manufacturers, such as Honda, have used axle-driven mechanical systems that limit power steering assist to low-speed driving situations. In other applications, steering pump pressure may be controlled by using a pulse-width modulation system that varies pressure in response to steering wheel demand and highway speed.

DIAGNOSTIC TIPS
On high-mileage vehicles with a steering wander complaint, the sector gear lash might require adjusting to eliminate excessive lash between the worm and sector gears. Early manual rack and pinion gears also have a similar adjustment that reduces lash between the pinion and rack gears.

A steering gear may also transmit steering feedback to the driver only when it’s installed in the centered position. In most cases, a four-wheel alignment may be required to recenter the steering gear. The first step is to always make sure that indexing marks on the steering wheel and steering shaft are aligned. The last step is to adjust front and rear toe angles to correspond with the vehicle’s centerline or thrust angle. When removing the steering wheel, always follow the manufacturers’ instructions regarding the disarming of the air bag and preventing damage to the air bag clock spring.

Any power steering gear can develop a “lack of assist” complaint. Generally speaking, a worn power steering pump is usually indicated if steering assist deteriorates as the steering oil begins to warm up and lose viscosity. In contrast, some rack and pinion steering gears may develop an intermittent condition called “morning sickness.” This particular lack of steering assist is caused by the metering valve oil seals wearing grooves into the soft aluminum steering gear housing. As the steering gear oil warms up, the valve assembly reseals itself to the housing and restores steering assist. Because special tools and expertise might be required to rebuild a steering gear, it’s more cost-effective to install a new or remanufactured gear than to repair or rebuild an old one.

Last, it’s always important to use application-specific power steering fluid in import applications. In the case of Honda, using non-OE specification fluid can ruin the steering gear seals. In other applications, using the wrong fluid or mixing fluids can cause the steering fluid to foam, which may cause a howling noise and temporary reduction of steering assist.

EGR ISSUES

Dealing with P0401 Codesby Bob DowieExhaust gas recirculation (EGR) has been used for years to control combustion temperature to prevent spark knock as well as control NOx emissions. For the most part, these systems were trouble-free and required service only if you were dealing with a spark knock issue, or if the valve opened too early, resulting in a tip-in acceleration stumble, or the more common, bad idle quality caused by the valve not closing completely at idle. As emission controls got tighter, and with the advent of OBD II, things started to change. We not only saw additional driveability complaints, but we also had the check engine light (CEL) telling the customer there was an emissions failure that had to be dealt with for the good of the environment and, in most states, to pass the annual vehicle inspection. In this article, we’ll take a look at some Honda EGR issues, which have also plagued the Acura line.

We’ll start with the four-cylinder Accord engines. While there have been some reports of problems with the Civic, problems with the Accord have been the most prevalent. Driveability complaints are more common than check engine lights on these models through the ‘90s. What you’ll be faced with is a stumble complaint, which is actually a misfire at part-throttle, that’s most prevalent on initial acceleration when the EGR valve is commanded to open. It feels almost like a bad wire and happens just when you’d expect a secondary ignition problem — part-load acceleration.

The cause of the misfire is an excess of recycled exhaust gasses in one or more cylinders. The cause of this excess flow is actually plugged passages in the manifold leading to the other cylinders. When there is no flow to those cylinders, the remaining cylinders receive all the exhaust gasses, which cause the miss. This problem has caused a great deal of frustration with techs, resulting in a lot of misdiagnosis. That’s not very surprising considering how well this problem mimics a secondary ignition problem. Then, to further confuse the issue, if there is a CEL, it’s often for the misfire and not the EGR system. Up until 1998, when the electronically controlled EGR valves were introduced, Honda looked at the EGR lift sensor to confirm that the valve received vacuum and opened, and that flow was taking place. Since the valve is opening, the ECU figures all is well there, but it’s well trained to pick up a misfire and is quick to report any problem that would hurt the catalytic converter.

MISDIAGNOSIS WOES
Often the combination of the obvious miss and the misfire code will send techs down the wrong path. Not that there’s anything wrong with checking the ignition system, but it takes only minutes to confirm if it’s the EGR system giving you a problem and not a bad wire or plug. Simply disable the valve and do a road test.

You’ll probably get a check engine light but, if the miss is gone, you’ll know for sure that the EGR system is the culprit. But don’t overlook checking the ignition components. It’s good to know the miss is fixed, but there’s never a bad time to bring the car up-to-snuff on maintenance items. Plus, you wouldn’t want the car coming back with a bad cap, wires or plugs next week if you could’ve taken care of those items now.

If disabling the EGR eliminated the miss, it’s time to clean out the passages. The procedure differs slightly depending on the year of the vehicle. The early cars used a blind core plug to seal the manifold runner EGR port after machining. We’ve found that the best way to remove these plugs is to drill a small hole partially into the plug, and using a self-tapping screw, or tapping the hole for a machine screw and using a small slide hammer, to pull them out. Partially drilling them will allow you to reuse the plugs if no replacements are on hand. Replacement plugs are available and there’s actually a kit from Honda that includes the tools and plug.

Needless to say, caution is required when drilling or tapping. Grease up the drill bit and tap to catch as many of the chips as possible. Using a shop vac is a much better choice than compressed air to keep the area clean as you work. With the plugs removed, the blockage will be obvious and can be easily dislodged using a stiff wire and carb cleaner. Be sure to clean the entire port again to keep the vacuum running. This procedure is well outlined in service bulletin #98-074, which should be available on your service information system.

The next era of four-cylinder cars saw the plugs replaced by a plate covering the EGR channel as well as the ports. This was a big improvement that eliminates the need to drill and allows us to better clean out any carbon buildup in the channel and the ports. Accessibility isn’t a problem, but the injectors will have to be removed. To be safe, you may want to have injector seals available, but they can often be reused. The latest of the four cylinders use a two-piece intake plenum with the EGR passages cast into the upper section. These cars don’t seem to suffer from the misfire problems of the earlier cars, but are more apt to have flow problems that will be picked up by the more observant OBD system setting a check engine light. To access the EGR ports and channel on these engines, split the intake and use a stiff wire to clean out the ports — a very similar procedure to the V6s that we’ll talk about next.

In recent years, EGR problems seem to be most prevalent on V-6 engines used in the popular Odyssey minivan, Accords and SUVs; only the worst cases will present driveability symptoms. It will be the check engine light providing the motivation for the customer, using the same enhanced code-setting criteria as the late-model four cylinders.

When Honda went to the electronically controlled sensor, they were now able to command the amount of lift, monitor the actual amount of lift and look at the MAP sensor making sure it had the expected effect on air flow. If anything unexpected happens on two trips, the check engine light will let the customer know.

The EGR passages on the six cylinders are in the upper section of the intake manifold. Some of the gaskets are reusable, but if you’re going in, the safe bet is to at least have a throttle body gasket on hand. To get started:

Remove the plastic throttle body and manifold covers, and remove the throttle body, leaving the electrical connectors, hoses and cables attached. Naturally, this is a great time to service the throttle plate.

Remove the upper manifold with the PCV attached.

With the manifold off, remove the chamber on the opposite side of the manifold from the throttle body along with the intake air temp sensor, PCV hose and brake booster nipple. These are removed to provide better access for cleaning the manifold when you’re done.

Using a 8mm (5/16”) drill bit as a hand-held ream, clean out the port. If you’re installing the update kit, now is when you’ll drill the manifold using the bit provided; be sure to follow the cautions included with the kit so as not to damage the manifold.

The next step is a thorough cleaning, flushing all the ports and intake runners from both directions. If you’re doing the update, now is also the time to install the EGR pipe.

Finish up by inspecting the EGR port in the manifold base and cleaning as required. This is best done with the EGR valve removed.

The aforementioned update kit is fully explained in Honda service bulletin #05-026, which also details the 8-year, 80,000-mile warranty extension for the EGR system. Many of these cars have been updated, but you’ll still see plenty of them with well over 80,000 miles that will be experiencing this problem, as well as some vehicles that aren’t covered in the bulletin. Nonetheless, the bulletin is a good resource to have.

CAUSES OF A P0401 CODE
While port restrictions are the most common cause of a P0401 code, that’s not the only reason you’ll see it. With the older vacuum-controlled EGR valves, there have been issues with the vacuum-switching valves being intermittent. Testing is straight-forward. With the engine running, be sure vacuum is available at the inlet side of the valve, then hook up the gauge to the hose leading to the EGR valve.

With the electrical connecter unplugged from the switching valve, introduce battery voltage to the black/yellow wire and apply ground to the red wire at the valve side of the electrical connector. If all is well, you’ll show vacuum on the gauge. As I said, these valves have a reputation for being intermittent, so repeat the test in quick succession looking for slow or no response on the gauge.

The electronic EGR valves are quite reliable but certainly haven’t been trouble-free; the problems we’re seeing with them are more about them sticking and not doing what they’re told. The good news is they’re not hard to diagnose when you know what you’re looking at. Let’s look at the connector on a 2002 model. We have five wires that handle valve operation and reporting; the valve is power-side controlled with a duty cycle signal from the ECU through the pink wire that gets its ground from the black wire.

On the reporting side, the yellow and blue is the 5V reference signal from the ECU for the position sensor, the green and black is ECU ground, with the white and black sending the signal back to the ECU, letting it know how the EGR is responding to direction. An increase in operational duty cycle should result in a smooth increase in reporting voltage with no dropouts. Many scan tools will let you look at and log command and reporting data on a road test. Otherwise, with good access, it’s not difficult to back-probe the connector and get the same info on a multi-channel graphing meter.

We can also use what we know about the wiring to check for blocked passages and the basic operation of the valve. With the electrical connector disconnected, the valve will open by putting battery power to the terminal that the pink wire is connected to and grounding the black wire terminal. If the ports are clear and the valve is working, the engine should quickly get rough or stall, and smooth out when the valve is closed.

When diagnosing a driveability problem, it’s important to keep in mind if you have a problem on light acceleration at low RPM, when the EGR is commanded on, suspect the EGR system. Or, an intermittent rough idle may be the result of the valve not completely closing. Otherwise, the EGR system shouldn’t be suspected.

If I can leave you with one solid tip for diagnosing and repairing EGR problems on the Honda line of vehicles, it’s to check your service information system for service bulletins. Honda does a great job of making this information available to the aftermarket, and it’s just foolish not to take advantage of it. If you’re not going online, checking for bulletins and making full use of services like iATN, import-car.com and OEM info like that available from Honda (www.techinfo.honda.com), you’re just leaving too much good information untapped. The way things are going, you won’t be able to afford doing that much longer.

On my automotive / car I have a bad voltage regulator, and do I have to replace my engine alternator? Houston,Tx

The voltage regulator controls or regulates the alternator’s output. Think of it as the brains of the charging system. It senses how much voltage is needed by your vehicle, then modifies the field current within the alternator so it puts out just the right amount of current. Too little current can allow the battery to run down while too much can damage it and other electrical and electronic components. When the regulator fails, the charging system usually ceases to function -- except in cases where the nature of the failure causes the alternator to run wild and overcharge the battery. In any event, the only cure for a dead or defective regulator is replacement. In older vehicles, the regulator was a separate component usually mounted somewhere in the engine compartment. If this type of regulator failed, it could be easily replaced in a matter of minutes with a new one. But for the last decade or more, most regulators have been mounted in or on the alternator itself. This was done by the vehicle manufacturers to simplify wiring and assembly. It was also made possible by advances in electronics that allowed the regulator to be reduced in size to a small chip. Charging systems that have a separate regulator mounted away from the alternator are referred to as "externally regulated" charging systems while those that have the regulator in or on the alternator are called "internally regulated" charging systems. On some vehicles there is no regulator at all! Voltage regulation is controlled by the engine computer. Unfortunately, internally regulated alternators are packaged as a unit -- which means that if either component fails (alternator or regulator) both must be replaced. This is because internal regulators are not available separately (at least not to the general public or the typical service facility). Electrical shops and remanufacturers who rebuild alternators can get them and can replace the regulator separately if that’s all that’s wrong with the unit -- but they’ll usually charge you the same as if you bought a rebuilt alternator. The truth is, the high cost of labor today has made it impractical for most service facilities to fool around trying to rebuild or repair components like alternators, starters, carburetors, front-wheel driveshafts, transmissions and even engines. It’s faster, easier and usually cheaper to simply replace the old unit with a new or remanufactured one than to try to overhaul or fix it. Besides, most new and remanufactured parts come with a guarantee.